The present invention relates to computer aided design (CAD) of integrated circuits (IC), and more particularly to improving wire routing in IC layout.
Wires in an integrated circuit are typically layers of conductive metal material such as copper or aluminum that are separated by layers of insulating material such as silicon dioxide. The metal layers are patterned using photolithographic techniques to form the wires for interconnecting the electrical elements in an integrated circuit. The layout design of a complex IC may, in part, be automated such that the location of interconnection wires is determined with the aid of CAD software called a router. For example, FIG. 1 shows part of an integrated circuit layout diagram generated by a conventional automated routing and layout tool. It can be seen that a wire 110 is placed to connect a contact pad 120 to a circuit 130.